Jobo 3005 8x10 streaks on negative

[Greg]

Tank: JOBO 2005
Film: 5 sheets Ilford FP-4+
Developer: 500ml Tetenal Ultrafin 1:19
Rotation: on a Stark SST4 set in the middle of the "speed-time" dial. Approximately 2.5 alternating rotations every 5 seconds
Pre-Soak: 1 minute minimum
Stop Bath: I use a very, very weak dilution of Kodak Indicator Stop Bath
Pour chemistry: Manually with tank at about a 60 degree tilt. Takes practice, but I am able to fill or drain the tank in about 10 seconds.

My JOBO literature recommends a minimum chemical volume of 270ml to 630ml. I was using less that 500ml, and every now and then got a bit of uneven development. Since increasing the volume to 500ml, I have had no problems with uneven development. With high dilutions of Rodinal, I increased the developer volume to 1,000ml.

[SergeyT]

Here is what I have done for years developing in an Expert tank with not a single issue
* Pre-soak for 4-5 minutes
* Constantly rotate in one direction only
* Take the tank off of the base and slightly tilt it to pour in chemicals (goes in much faster and with no spills)

With other tanks I had uneven development before but suspect mostly by not using enough of developer

[Fred L]

I wonder if filling the tank fully during the pre soak is what might the problem. If the chambers are full, there's not much sloshing around, which is iirc, essential to proper development. fwiw, I stopped presoaking and either use my Jobo CP-2 or if I'm at another lab, the Simma roller. Tilting the tank, I can fill pretty quickly, maybe 10-15 seconds ?

Hope you can figure this out, 8x10 film definitely ain't cheap

[Vaughn]

I checked the time I use to fill the 3005 -- 30 seconds give or take a couple to pour a liter into the horizontal 3005 using a hose (no funnel) while it is turning on the motor base (Unicolor w/ auto rotation direction change disabled).

Something to think about; My drum is turning at 16 RPM, or 8 revolutions in 30 seconds, or about 1 revolution in 4 seconds. The time it takes me to pour the first 250ml into the drum is about 8 seconds. In this first 8 seconds, the drum turns two times and now contains enough fluid to meet the minimum requirement (270ml) to work efficient. The time it takes to fill the remaining 730ml is not as critical as the drum has sufficient developer to be working on all cylinders and the rest helps with capacity and even development...and is quickly on its way.

As long as one gets even development in one's system, one is gold! (or silver)

[cowanw]

I had your problem as well. after using the drum for years, I changed to using completely mixed developer solution and this happened.. It is a filling problem, not prewash nor rotation problems.
Either fill the drum with most of the plain water that would be used to mix the correct concentration of developer. Then add the required developer so that it dilutes into the larger volumn.
Better, while the drum is rotating on it's base, fill with a large diameter tube and large funnel using the plain water that will make up most of the final dilution and at the end of the fill add the developer to the funnel. coarse clear tubing at Home Depot or such has 1/8 inch wall that stay a bit curved of the store roll and sit loosely in the hole of the drum. The larger the funnel the better.

[Bernice Loui]

Been using Jobo 3006 drum since the 90's to this day. Never had any streaking problems all that duration.

~Use the Jobo recommended chemistry volume, never exceeded these volumes.

~Filtered water fill/rinse about 30 seconds, no pre-soak.

~Fill time about 15 seconds. Drain time about 20-30 seconds.

~Jobo processor speed between 30 to 70 rpm during developing.

~Nitrogen purge for Pyro developers.


Bernice

[howlingsun]

There was no streaks in the second batch. Everything looks great. The filling went much better this time it felt like, so I will keep doing that or improving the process then see if the streaks come back.

[Vaughn]

Excellent!

[Ari]

I cant help but think that its connected to the slow process of pouring in the chemicals without rotation. That would explain the look of the streaks to me. They come from the top and run down, like drops on a window or shower glass wall.

I tend to agree.
The 3005 isn't meant to be filled, the label on the tank tells you how much solution to use.
The sloshing of the solution is critical to success, so use less water for pre-rinse and fill the tank faster with developer.
I pre-rinse all the time and never had a problem due to that, so I think the quantity of water is the issue.
If you cut off the top of a large soft drink bottle and attach it to a hose, you can use that to fill the tank while it's rotating, or lying flat.
It shouldn't take more than 15s.

[esearing]

I wonder if more agitation in the first minute or two would solve the problem? Also - don't burn 5 sheets of 8x10 on a new process unless you have deep pockets.